CN1942418B - Ways to Dispose of Garbage - Google Patents

Abstract

A method for processing refuse including organic and non-organic materials, characterised in that it comprises the steps of (A) admixing quick lime and at least one highly slaked substance to said refuse, (B) allowing said organic materials to react to give a product that includes a calcium organic complex and said non-organic materials, and (C) separating said non-organic materials from said calcium organic complex.

Description

Ways to Dispose of Garbage

technical field

The invention relates to a method for treating garbage. the

Background technique

From the document WO 01/85646 is known a method of treating refuse, wherein the refuse is mixed with quicklime and strongly hydrated substances such as sludge and/or grease from purification stations, the mixture is chemically reacted for a period of time and then ground The dehydrated product from this reaction was crushed. the

In the prior art method described above, inorganic matter, which cannot be subsequently extracted by pneumatic means (cyclones, etc.), is extracted from the waste before it is mixed with quicklime and strongly hydrated substances. These pre-extracted inorganic substances include, inter alia, glass, ferrous and non-ferrous metals, and the like. the

However, such prior extraction by conventional picking devices is generally not easy. the

It should be taken into account that, in practice, the inorganic matter in these wastes tends to stick to the organic matter, making it difficult to separate the two substances. the

Contents of the invention

The aim of the present invention is in particular to eliminate the above-mentioned disadvantages. the

This object is achieved by a method of treating waste comprising organic matter and inorganic matter, the method being characterized in that it comprises the following steps:

A) mixing quicklime and at least one strongly hydrating (hydrating) substance with said waste;

B) reacting said organic matter to obtain a product comprising a calcium organic complex and said inorganic matter;

C) separating said inorganics from said calcium-organic complexes. the

The reaction that takes place between the organic matter of the waste, the quicklime and the strongly hydrating matter dehydrates the organic matter and thus obtains a product in which the (unreacted) inorganic matter can easily be combined with the product's The remainder is separated, that is, separated from the calcium-organic complex. the

Therefore, these inorganic substances can be separated from calcium-organic complexes very easily by conventional means. the

Other optional features of the method according to the invention are as follows:

- the method comprises a step D) of sorting the inorganic matter obtained at the end of step C);

- the method comprises step 0), i.e. dividing said garbage according to a predetermined granularity before step A);

- re-injecting at least a part of said calcium organic complex obtained at the end of step C) into the mixture of step A);

- the method includes step E), that is, screening the calcium organic complex according to a predetermined particle size;

- Substances that are strongly hydrating substances are selected from the group including sludge and grease from purification stations;

- adding to the mixture of step A) at least one compound selected from the group consisting of: green waste (unripe waste), fibrous matter, manure, bird and animal droppings, peat;

- Step B) is carried out using a closed zone with an active bottom;

- Use a static enclosure to implement step B);

- carrying out steps C) and/or D) and/or E) using the following separation and sorting devices selected from the group consisting of screening devices, magnetic devices, eddy current (courant de Foucault) devices and gravity devices. the

The invention also relates to a device for carrying out the above-mentioned method according to the invention, characterized in that, in order from the point of entry of the waste to be treated, the device comprises the following means:

- means for mixing said waste with said quicklime and said strongly hydrated substances;

- means for allowing the reaction to proceed; and

- A device for separating said inorganics from said calcium-organic complexes. the

Other optional features of the device are as follows:

- the plant also includes means for sorting the inorganic matter obtained at the end of step C);

- the device comprises, upstream of said mixing means, means for dividing said waste according to a predetermined particle size;

- the device comprises, downstream of said separation means, means for screening said calcium-organic complexes according to a predetermined particle size;

- said means for allowing the reaction to proceed comprises an enclosure with a movable bottom;

- said means for allowing the reaction to proceed comprises a static enclosure. the

Description of drawings

Other features and advantages of the present invention will become apparent by reading the following description and referring to the only accompanying drawing, in which:

Figure 1 schematically shows the main steps of the method according to the invention. the

Detailed ways

According to the preamble of this specification, in the ensuing description (description and claims), the term "inorganic substances" refers specifically to substances that cannot be extracted from garbage by pneumatic means (cyclone separators, etc.) after a chemical reaction with quicklime Inorganic matter. the

These inorganic substances include glass, ferrous metals and non-ferrous metals, among others. the

The waste to be processed is preferably domestic waste, which usually arrives at the disposal station after being packed in plastic bags in the receiving area. the

Typically, such a receiving area may consist of a number of metal boxes with a movable bottom, which operate according to the FIFO (First In First Out) principle. the

This waste usually includes both organic and inorganic matter. the

Preferably starting with step 0, in which the garbage bags are sheared and/or ground and/or shredded to obtain pieces with a predetermined particle size (typically about 80-100mm). the

In step A, quicklime (CaO) and at least one strongly hydrating substance are mixed with the refuse. the

As an example, strongly hydrating substances may include sludge and/or grease from purification stations. the

The mixing operation may be carried out by any suitable means known to those skilled in the art, for example means comprising a screw rotating within a mixing vessel. the

In step B, a chemical reaction is carried out between the garbage, quicklime and strongly hydrated substances. the

As known in the prior art, this chemical reaction can be expressed as follows:

Organic matter + CaO + H ₂ O → calcium organic complex + CO ₂ + H ₂ O (water vapor) + other gases (NH ₃ , NH ₄ ...).

This strongly exothermic reaction can be carried out in a static closed area such as a pool (pit) or a closed box. the

However, it is preferred to use a device with a movable bottom, a device of the type described in patent application PCT/FR00/01250 published on November 15, 2001 with publication number WO 01/85645. the

The time required for the above-mentioned chemical reaction is more than 30 minutes, approximately between 2-4 hours. the

After step B has been completed, a product with greatly reduced moisture content, ie a product with a dry appearance, is obtained. the

The product includes both the organic calcium complex resulting from said chemical reaction and said inorganic substance, which is inert with respect to the chemical reaction. the

Due to the low moisture content of the product obtained after step B, it is very easy to separate inorganic substances (ferrous and non-ferrous metals, glass, etc.) D picks out these inorganic substances. the

Apparatus for separating inorganics from calcium-organic complexes and for sorting inorganics are conventional and may typically include:

- screening device;

- ("overband" type) magnetic devices for the extraction of ferrous metals;

- eddy current device for extraction of non-ferrous metals;

- (vibrating table type) gravity device for separating the lightest element from the heaviest element, etc. the

In step E, the calcium-organic complex is screened to obtain a powdered product with a particle size usually between 0 and 20 mm or larger if necessary. the

In this way a product is obtained which is an organic calcium-rich fertilizer which is particularly suitable for agricultural use. the

It should be noted that it is conceivable to add other carbon compounds to the mixture of step A, for example green waste (eg cut grass), fibrous matter (paper, cardboard), manure, bird droppings, peat, etc. the

It should also be noted that at least a portion of the calcium organic complex (see reference number 1 in the drawing) can be reinjected into the mixture of step A. the

This operation makes it possible to obtain an appropriate ratio of organic matter and quicklime in the mixture of step A, and thus finally obtain a product whose composition is always substantially the same. the

Therefore, the invariance constraints imposed in the current regulations can be respected. the

As an illustrative and non-limiting example, the weight ratios of the components of the chemical reactions mentioned above are as follows:

- Substances constituting garbage: 20% to 70%;

- quicklime: 10% to 30%;

- Strongly hydrated substances (water that may contain organic matter): 10% to 60%. the

As can be understood from the foregoing, the present invention can very easily separate inorganic matter and organic matter because all garbage is dehydrated. the

Since after step B the inorganics have become "hygienic" - ie they no longer contain pathogenic and/or putrid substances, the invention can also facilitate the sorting of these inorganics. the

Since after step B the inorganic matter no longer poses a threat to humans, manual sorting is also conceivable. the

Of course, the present invention is not limited to the above embodiments which are merely illustrative examples. the

Claims (16)

1. A method for processing garbage comprising organic matter and inorganic matter, said inorganic matter refers to the inorganic matter that cannot be extracted from garbage by pneumatic means after utilizing unslaked lime to carry out chemical reaction, it is characterized in that, the method comprises the following steps: A) mixing quicklime and at least one strongly hydrating substance with said refuse; B) reacting said organic matter, said quicklime and said strongly hydrated matter to obtain a product comprising calcium organic complexes and said inorganic matter; C) separating said inorganics from said calcium-organic complexes. 2. The method according to claim 1, characterized in that it comprises a step D) consisting in sorting said inorganic matter obtained at the end of step C). 3. The method according to claim 1 or 2, characterized in that the method comprises step 0), which consists in dividing the garbage according to a predetermined granularity before step A). 4. The method according to claim 1 or 2, characterized in that at least a part of the calcium-organic complex is reintroduced into the mixture of step A). 5. The method according to claim 2, characterized in that it comprises a step E) consisting in screening said organic calcium complexes according to a predetermined particle size. 6. The method according to claim 1 or 2, characterized in that the substance being a strongly hydrating substance is selected from the group comprising sludge and grease of purification stations. 7. The method according to claim 1 or 2, characterized in that at least one compound selected from the group consisting of: green waste, fibrous matter, manure, bird and animal droppings, peat is added to the mixture of step A). 8. Method according to claim 1 or 2, characterized in that step B) is carried out using an enclosed zone with a movable bottom. 9. The method according to claim 1 or 2, characterized in that step B) is carried out using a static enclosure. 10. The method according to claim 5, characterized in that steps C) and/or D) and/or E) are carried out using the following separation and sorting devices selected from the group consisting of screening devices, magnetic devices, eddy current devices and gravity device. 11. An apparatus for carrying out a method according to any one of the preceding claims, characterized in that, in order from the point of entry of the waste to be treated, the apparatus comprises the following means: means for mixing said waste with said quicklime and said strongly hydrating substance; means for allowing said reaction to proceed; and Apparatus for separating said inorganics from said calcium-organic complexes. 12. The plant according to claim 11 for carrying out the method according to claim 2, characterized in that it also comprises means for sorting the inorganic matter obtained at the end of step C). 13. Apparatus according to claim 11 or 12 for carrying out the method according to claim 3, characterized in that said apparatus comprises, upstream of said mixing means, means for dividing said waste according to a predetermined particle size . 14. Apparatus according to claim 11 or 12 for carrying out the method according to claim 5, characterized in that said apparatus comprises, downstream of said separation means, a device for screening said reuse fraction according to a predetermined particle size installation. 15. Apparatus according to claim 11 or 12 for carrying out the method according to claim 8, characterized in that said means for allowing said reaction to proceed comprise an enclosed zone with a movable bottom. 16. Apparatus according to claim 11 or 12 for carrying out the method according to claim 9, characterized in that said means for allowing said reaction to proceed comprise a static enclosure.

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